Digital imaging units and the like use sensor panels to capture a frame of image data to produce a still picture, or a sequence of such frames to produce a video. A sensor panel may be, for example, a charge-coupled device (CCD) that essentially consists of an array of sensor elements, each element generally equivalent to a pixel.
Variability between sensor elements may introduce biases into the captured image data. The sensor elements in the camera's sensor panel may differ from one another to some degree due to, for example, tolerable variations introduced during fabrication. Thus, for example, if a digital camera is used to take a picture of an object that is a certain shade of red, then some sensor elements may measure shades of red that are different from the actual shade.
There are products known as frame grabbers that can grab or separate an individual frame from a sequence of video frames. A frame grabber is typically implemented as an add-in card that is plugged into the motherboard of a conventional computer system. In some implementations, frame grabbers may process each frame of the image (still or video) data in some manner so that the data can be viewed in a more meaningful way. For example, a sensor panel can be calibrated against benchmark images to quantify a correction factor for each sensor element in the sensor panel. The element-specific (e.g., pixel-by-pixel) correction factors for a particular sensor panel can be loaded into memory onboard the frame grabber and subsequently applied by the frame grabber to the raw image data (e.g., pixel values) captured using that sensor panel. In this manner, the raw image data is corrected so that it more accurately reflects the actual (real world) attributes of an object being imaged.
Unfortunately, a large amount of memory is needed to store the calibration data used to correct the raw image data. Consequently, frame grabbers that provide processing capability can be costly to produce and maintain.